Rotatable eartip stethoscope

ABSTRACT

A stethoscope having eartips rotatably mounted on its sound tubes, permitting the tubes to move relative to the eartips without traumatizing the ear canals of the stethoscope user.

United States Patenfi 1 1 Peart 14 1 Jan. 16,1973

541 ROTATABLE EARTIP STETHOSCOPE 2,755,880 7/1956 Hofmann ..181/242,803,308 8/1957 Di Maltia.... [75] Inventor: Edward Lynn Peart, Arden,2,939,923 6/1960 Henderson Buncombe,N.C. 3,415,246 12/1968 H111 ..18l/23[73] Assignee: Sybron Corporation, Rochester,

. N.Y. Primary ExaminerStephen J. Tomsky [22] Filed: June Att0rnev--The0dore B. Roessel 21 A LN 151470 1 pp 0 57 ABSTRACT U-S. .1 181/24,A 'stethoscope having eanips rotatably mounted on its [51] Int. Cl...A6lb 7/02 sound tubes, permitting the tubes to move relative to [58]Field of Search ..l8l/24, 23; 179/182 the eartips without traumatizingthe ear canals of the stethoscope user. [56] References Cited UNITEDSTATES PATENTS 6 5" 9 Drawing 2,521,414 9/1950 Schier ..18l/23PATENTEDJANIBIBH 3.710.888

INVENTOR.

// I E. L. PEART 1 ROTATABLE EARTIP s'rn'rnoscorrz FIELD OF THEINVENTION SUMMARY OF tI-IE INVENTION In the present invention, theeartips are rotatably mounted on the sound tubes. The ear canals of ahuman user are more or less cylindrical, and the axis of rotation of thetips is selected to be the cylinder axis of the ear canal, or parallelthereto. The rotatability of the eartips need not be so restricted, andin another form of the invention, the eartips are connected to the soundtubes by ball and socket joints, so that when the eartips are in placein the ear canals, the axis of rotation between sound tubes and eartipscan have any angular orientations whatsoever.

However, the more restricted rotatability suffices since itsubstantially eliminates, completely, tangential stress on the ear canaltissues. While this permits some stress to'be exerted transverse to theaxis of rotation, and along it, the usual movement of the stethoscope isnot in such directions as would produce these types of stress, and,further, the ear canals are less vulnerable thereto.

BRIEF DESCRIPtION OF THE DRAWING FIG. 1 is a diagram for use inexplaining the principles of the present invention, as applied to atypical stethoscope-use situation;

FIG. 2 is a diametral sectional view of a stethoscope eartip accordingto the invention, the section corresponding to the plane of the sectionA of FIG. 3, and the proportions of the Figure being 6% times those ofan actual example of the eartip;

FIGS. 3 and 4 are opposing end elevations of the eartip of FIG. 2; and

FIG. 5 is a side elevation thereof, the proportions of FIGS. 3, 4 and 5being about twice those of an actual example of the eartip; and

FIGS. 6 and 7 are views analagous to those of FIGS. 2 and 3respectively, but of a second fonn of the invention, wherein a ball andsocket arrangement provides eartip rotatability, and

FIGS. Band 9 are views analogous to that of FIG. 6 but of additionalforms of the invention.

In FIG. 1, reference numeral 1 denotes a section through the head of ahuman user of a stethoscope denoted generally by reference numeral 2.The section is to be supposed to more or less bisect the ear canals 3and 4 of the user's head. For simplicity, the canals are also deemed tobe substantially coaxial right cylinders, the common axis of which isthe X axis of the XYZ coordinate system diagrammed between the earcanals.

Stethoscope 2 has ear tips 5 and 6 in place in canals 3 and 4. The tipsterminate rigid sound tubes 7 and 8,

which are normally biased toward each other by a suitable U-shaped leafspring 9, the ends of which terminate in fittings I0 and 11 or the likewhich fix the lower ends of tubes 7 and 8 to the ends of the spring 9.Fittings 10 and 11 connect the upper ends of flexible sound tubes 12 and13 to the lower ends of tubes 7 and 8.

At their lower ends, tubes 12 and 13 are interconnected by a fitting 14to one end of sound tube 16. A sound pick-up l7 terminates the other endof tube 16. In use,.sound intercepted by pick-up 1 7 is conductedthrough tube 16 to fitting 14, whence it passes to sound tubes 7 and 8via sound tubes 12 and 13, eventually being emitted into the ear canals3 and 4 through tips 5 and 6.

As thus far described, FIG. 1 will be recognized as depicting the usualconfigurationof stethoscope and user. The actual geometry of the anatomyof the human head is somewhat more elaborate, for instance, the earcanal is actually a bit sinous, varies in diameter along its length, andhas an effective axis diverging downwardly from the X axis. However, forthe purposes of the present invention, the illustrated geometry issufficiently accurate.

In any event, from the time the user dons the stethoscope, thestethoscope in general undergoes a good deal of bodily motion. However,this occurs with tips 5 and 6 rather solidly fixed in place. Thus, thenormal condition of spring 9 is to hold the tips much closer togetherthan illustrated, so that to don the stethoscope, the user has to spreadthe tubes 7 and 8 apart, and the tips are a-quite snug fit in the earcanal. As a result, there is a rather substantial spring force trying topush the tips deeper into the ear canals, and a rather substantialfrictional force between the circumferential surface of the eartips andthe ear canal tissue in contact therewith.

The user normally grasps the stethoscope at about the pickup 17, whichgives him a very substantial leverage on all axes passing through thelocations of the eartips. As the ear canal tissue is quite delicate, itis evident that such leverage can easily be used to the detriment ofsuch tissue. As it happens, this tissue is most vulnerable to the mostlikely application of that leverage, which is to move the stethoscope insuch sense as to deflect the tubes 7 and 8 about the x axis, forexample, in the sense of the arc C which lies in the YZ plane (theZ-axis, of course, is normal to the section plane represented byreference numeral 1, but had to be shown in perspective in order to besufficiently visualizable).

To put it another way, the stethoscope is, in effect,

fixed to the ear canal tissue. In comparison to the'ear tissue, thestethoscope structure between fitting l4 and the tips is quite rigid, sothat if the ear tips move when the rigid structure is moved, the eartissue distorts to allow such motion. As the tissue is delicate, thedistortion is likely to be tramatic, causing temporary discomfort, atleast, and not infrequently, an actual lesion of the tissue, especiallyif the trauma is recurrent, due to frequent use of the stethoscope. Itwill be noted that stresses along the X axis are much less likely to betraumatic, at least when it comes to causing lesions. The reason forthis is that the ear canal converges, so that some of the force due tospring 9 is absorbed by comtion of the ear canal tissue.

an ear canals.

Received within sleeve 19, is asleeve 26. Sleeve 26 is right-cylindricalin outer contour and fits the inner pression of the outer layers oftissue against inner, more solid tissue. However, forces tangential tothe inner surface of the ear canal'tends to peel the outer layers fromalmost continuously acts in a way inviting traumatiza- I Mysolution tothis problem is to provide a rotatable connection between theear tips 5and 6, and the tubes- 7 and 8, wherein each of such connections has atleast one axis ofrotation and that axis is along the X-axis, inpractice, slightly skewed therefrom, for, as pointed out before, theeffective axis of the actual ear canal diverges somewhat from theX-axis.

In FIG. 2, the eartip 6 (and of course, eartip 5) is shown to bea-sleeve 19 having fixed thereto a collar 20. The inner volume of thesleeve is right cylindrical, over which volume flange 21 of the sleeveextends to define an'aperture 22. From flange 21 projects a flange 23which fits into a corresponding slot in the end of collar 20, with theflared central aperture 24 registering at its narrower side with theaperture 22. Typically, sleeve 19 would consist of metal or other rigidmaterial, whereas collar would consist of a soft material, inparticular, neoprene. The sleeve 19 and collar 20 for all practical"purposes must define a single, integral member, so preferably they arebonded together by vulcanization or other means which will both hold thetwo together and-hermetically seal the collar 20 to the flange 21,continuously around the periphery of aperture 22.

As will be seen from FIG. 2, collar 20 flares outwardly through an angleof 180 to terminate in a portion 25 thereof, of reduced thickness. Theproportions of H6. 2 are to exact scale of an actual example of aneartip according to the invention. However, the basic desiderata arethat the largest diameter of collar 20 is just large enough to create ahermetic seal between the tissue of the ear canal surrounding portion25, and the portion 25'. The configuration shown in FIG. 2, with aneopreneflange, allows the cross-section of collar 20 to be circular andstill seal the ear canal, which is actually somewhat elliptical incross-section. A material harder than neoprene could be used if thecollar were given elliptical cross-sectiomGenerally speaking, the harderthe material of collar 20, the more nearly it must conform to the actualear canal contour. As this is not conducive to manufacturing economy, orto ease of use, it is preferable to use soft enough material in order toachieve a single size and configuration which will suit volume of sleeve19 as closely as possible, without filling it so closely as to preventsleeve 26 from rotating freely in sleeve 19. I

Sleeve 26 has a flange 27, analogous to flange 21, the former definingan aperture 28 which registers with aperture 21. Unlike flange 21, thesurface of flange 27, next adjacent flange 21, has a smooth flat finishmating with a similar finish on the surface of flange 21 nextadjacent-flange 27. As will be seen from FIG. 2, sleeve 26 is asubstantially perfect fit except at a flange 29 of the left end-ofsleeve 19. The flange 29 does not exist until after the sleeve 26 hasbeen inserted in sleeve 19 during manufacturing. After such insertion,the end of sleeve 19 is swaged over as shown, allowing a slightclearance between flange 29 and the left end of sleeve 26, in order toassure that the latter can continue to be freely rotatable in sleeve 19.

The fit between sleeve 19 and sleeve 26 need notbe v especially close inorder to prevent sound transmission v throughthe slight annularclearance between the inner surface of sleeve 19 and the outer surfaceof sleeve 26,

because when the tips are in place in the ears, spring 9 the bore 32 ofwhich is toregister with aperture 28. To

assembly the tip 6 to the tube 8, a suitable tool is insertedthroughhole 30 in sleeve 19 into hole 31 in sleeve 26 so that the sleeve 26 canbe screwed tightly on end 18. Sleeve'26 should be tightly secured to end18 in order to assure that no sound is transmitted via the intersticesbetween the threads, as well as toassure that the eartip will not workloose from tube 8.

The sleeve 26 could be threaded on step 18 before being assembled tosleeve l9,'in which case flange 29 would have to be formed after the tipis'in place on tube 8. It this instance, sleeve 26 could be formed as an"integral part of the end of tube 8. However, these variants, whilewithin'the scope of the invention, have their drawbacks. For instance,it would be most inconvenient to the user if he had to replace aneartip, as he is not likely to be prepared to perform the swaging step.

Withthe FIG. 2 embodiment, however, it is not difficult for the user toscrew on a new eartip while blocking rotation between the sleeves 19 and26.by means of the end ofa commonpaper clip, say.

In an actual example of an eartip according to the invention, collar 20consisted of neoprene, andsleeves l9 and 26 consisted essentially ofaluminum and thermoplastic acetyl resin, respectively.

In the form of the invention shown in FIG. 6, a ball 33 and socket 34provide eartip rotatability'. Socket 34 corresponds to sleeve 19, andhas a collar 35 corresponding to collar 20, and extending continuouslyaround the periphery of the socket. In order to take advantage or theuniversal rotatabilit y of the ball. 33, socket 34 is provided 'with a'circular aperture 36,

somewhat larger in diameter'than the sound transter than sound tube 8which projects through aperture 38 into ball 33, to which it is fixed byany suitable means (not shown), with its bore 32 communicating withaperture 37.

FIG. 7 shows the collar 35 as being somewhat oblong, in order toillustrate the possibility of providing a better fit to the contour ofthe human ear canal. However, the collar 35 may be circular, as in thecase of its counterpart collar 20.

It is to be observed that the collar 35 (and collar 20) by its very formprovides a certain amount of flexibility, and so widens the range ofmaterials that may be used for the collars, including those materialswhose intrinsic flexibility is not in itself enough to be entirelycomfortable if plugged into the ear canal firmly enough to seal thecanal. A similar result is obtained in the form shown in FIG. 8, where adoughnut like tip 39 is provided, which is hollow, as shown at 40, andmay have a filling of air or liquid. Here, the thinness of the doughnutwall together with the intrinsic flexibility of the wall material(rubber, plastic, or the like), provides for a comfortable seal of theear canal. Reference numeral 41, denotes the rotatable coupling betweendoughnut 39 and sound tube 8.

FIG. 9 is similar to FIG. 8 except that a solid doughnut 42 iscontemplated. In this case, the material of doughnut 42 must besufficiently intrinsically resilient to provide a comfortable sealof theear canal. Finally, it is also within the scope of the invention toprovide an exact fit of the eartip to the ear canal, over sufficientlength of the latter that the canal is adequately sealed withoutsubstantially distorting the canal, in which case the eartip may be madeof quite rigid material such as bakelite.

Having set forth my invention as required by 35 USC l 12, I claim:

1. A stethoscope including first, second, and third tubes, first andsecond eartips, and a pickup;

said first eartip being on one end of said first tube,

said second eartip being on one end of said second tube, and said pickupbeing on one end of said third tube;

the other ends of said tubes being joined together for transmission ofsound from said pickup to said cartips;

said first'and second tubes having flexible portions,

and said stethoscope having means biasing said one ends thereof towardeach other for causing the said tips to be closer together thanintra-aural distance, except when in place in a users ears;

said first eartip having a passageway therethrough communicating withthe passageway of said first tube and opening into the canal of a usersear when said tip is in place in said ear;

said first eartip being externally constructed to substantially sealsaid canal, when in place, as aforesaid, and said stethoscope havingmounting means mounting said eartip rotatably and sealingly said one endof said first tube for rotation with respect to said one end while inplace in said canal, and on an axis approximately the same as that ofsaid canal;

said second eartip being the same as said first eartip, and beingmounted on said one end of said second tube, in the same way;

said mounting means being a first sleeve fixed to one end of said firsttube, and said eartip including a second sleeve rotatably fitting theoutside of said first sleeve, but being restrained from movement axiallyof said first sleeve;

said first sleeve having fastening means removably fastening it to saidone end of said first tube, said fastening means being of the typerequiring access to the exterior of said first sleeve, and said secondsleeve having a hole in the side thereof for providin such access. 2. estethoscope of claim 1, wherein said eartip has an annular flexiblecollar projecting therefrom transverse to the effective axis of saidcanal and said mounting means provides for rotation of said eartip on anaxis transverse to the direction of projection of said collar.

3. The stethoscope of claim 1, wherein said fastening means includesthreads on said first tube and threads inside said first sleeveengageable with the former said threads by rotation of said secondsleeve with respect to said first sleeve; said first sleeve having atool-engageable element located for allowing access thereto via saidhole.

4. The stethoscope of claim 3, wherein said second sleeve has an annularflexible collar projecting radially therefrom.

5. The stethoscope of claim 3, wherein said tool-engageable element is ahole in the side of said first sleeve.

6. The stethoscope of claim 5, wherein said second sleeve has an annularflexible collar projecting radially therefrom.

1. A stethoscope including first, second, and third tubes, first andsecond eartips, and a pickup; said first eartip being on one end of saidfirst tube, said second eartip being on one end of said second tube, andsaid pickup being on one end of said third tube; the other ends of saidtubes being joined together for transmission of sound from said pickupto said eartips; said first and second tubes having flexible portions,and said stethoscope having means biasing said one ends thereof towardeach other for causing the said tips to be closer together thanintra-aural distance, except when in place in a user''s ears; said firsteartip having a passageway therethrough communicating with thepassageway of said first tube and opening into the canal of a user''sear when said tip is in pLace in said ear; said first eartip beingexternally constructed to substantially seal said canal, when in place,as aforesaid, and said stethoscope having mounting means mounting saideartip rotatably and sealingly said one end of said first tube forrotation with respect to said one end while in place in said canal, andon an axis approximately the same as that of said canal; said secondeartip being the same as said first eartip, and being mounted on saidone end of said second tube, in the same way; said mounting means beinga first sleeve fixed to one end of said first tube, and said eartipincluding a second sleeve rotatably fitting the outside of said firstsleeve, but being restrained from movement axially of said first sleeve;said first sleeve having fastening means removably fastening it to saidone end of said first tube, said fastening means being of the typerequiring access to the exterior of said first sleeve, and said secondsleeve having a hole in the side thereof for providing such access. 2.The stethoscope of claim 1, wherein said eartip has an annular flexiblecollar projecting therefrom transverse to the effective axis of saidcanal and said mounting means provides for rotation of said eartip on anaxis transverse to the direction of projection of said collar.
 3. Thestethoscope of claim 1, wherein said fastening means includes threads onsaid first tube and threads inside said first sleeve engageable with theformer said threads by rotation of said second sleeve with respect tosaid first sleeve; said first sleeve having a tool-engageable elementlocated for allowing access thereto via said hole.
 4. The stethoscope ofclaim 3, wherein said second sleeve has an annular flexible collarprojecting radially therefrom.
 5. The stethoscope of claim 3, whereinsaid tool-engageable element is a hole in the side of said first sleeve.6. The stethoscope of claim 5, wherein said second sleeve has an annularflexible collar projecting radially therefrom.